Power converter

Abstract

The power converter (1) comprises a plurality of units (13a, 13b, 13c, 13d), a cooling pipe (4), and a rack (20). Each of the plurality of units (13a, 13b, 13c, 13d) includes a plurality of submodules (10). The cooling pipe (4) is connected to the plurality of submodules (10). The rack (20) supports the cooling pipe (4). The rack (20) includes a plurality of support rods (21, 22) and a plurality of plates (23, 24, 25, 26) stacked via the plurality of support rods (21, 22). The cooling pipe (4) is fixed to at least two of the plates (24) and is meandering.

Description

Technical Field

[0001] The present disclosure relates to a power conversion device.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2020-150746 (Patent Document 1) discloses a power conversion device including a base, insulating columns, a plurality of modules, and a plurality of insulating pipes. The plurality of modules are vertically stacked on the base via the insulating columns. The ends of the plurality of insulating pipes are connected to joints provided on the side surfaces of the modules and the base. A cooling medium is supplied to the plurality of modules through the plurality of insulating pipes. The plurality of insulating pipes are arranged obliquely with respect to the vertical direction between adjacent modules among the plurality of modules.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the power conversion device disclosed in Patent Document 1, the ends of the plurality of insulating pipes are merely connected to the joints. Therefore, the seismic resistance of the plurality of insulating pipes is low, and the seismic resistance of the power conversion device is low. The present disclosure has been made in view of the above problems, and an object thereof is to provide a power conversion device having improved seismic resistance.

Means for Solving the Problems

[0005] The power converter of this disclosure comprises a plurality of stacked units, support insulators supporting the plurality of units, cooling pipes, and a rack supporting the cooling pipes. Each of the plurality of units includes a plurality of submodules. The cooling pipes are connected to the plurality of submodules. A refrigerant for cooling the plurality of submodules is supplied to the plurality of submodules through the cooling pipes. The rack includes a plurality of support rods and a plurality of plates stacked via the plurality of support rods. The cooling pipes are fixed to at least two of the plurality of plates and are meandering. At least two plates are positioned below the lowest unit of the plurality of units. [Effects of the Invention]

[0006] The power converter of this disclosure provides a power converter with improved seismic resistance. [Brief explanation of the drawing]

[0007] [Figure 1] This is a circuit diagram showing the overall configuration of the power conversion device. [Figure 2] This is a schematic circuit diagram of the submodule. [Figure 3] This is a schematic front view of the power conversion device according to the embodiment. [Figure 4] This is a schematic left side view of the power conversion device according to the embodiment. [Figure 5] This is a schematic right side view of the power conversion device according to the embodiment. [Figure 6] This is a schematic, partially enlarged left side view of region VI shown in Figure 4 of the power converter according to the embodiment. [Figure 7] This is a schematic partial enlarged plan view of the power conversion device according to the embodiment. [Figure 8] Figure 3 shows a schematic enlarged cross-sectional view of region VIII of the power converter according to the embodiment, and Figure 7 shows a schematic enlarged cross-sectional view of the power converter according to the embodiment along the cross-sectional line VIII-VIII. [Figure 9]This is a schematic, partially enlarged left side view showing the creepage distance of the rack. [Figure 10] This is a schematic partial enlarged plan view of a power conversion device according to the first modified embodiment. [Figure 11] This is a schematic partial enlarged plan view of a power conversion device according to a second modified example of the embodiment. [Modes for carrying out the invention]

[0008] Embodiments of the present disclosure will be described below. The same components will be given the same reference numerals, and their descriptions will not be repeated.

[0009] The circuit configuration of the power converter 1 of this embodiment will be described with reference to Figures 1 and 2. The power converter 1 of this embodiment is not particularly limited, but for example, it is a modular multilevel converter (MMC) type high-voltage direct current (HVDC) converter.

[0010] Referring to Figure 1, the power converter 1 is connected to the AC power system 100 via a transformer 101. The power converter 1 is connected to the DC power system 102. The power converter converts the AC power input to the AC power system 100 into high-voltage DC power and outputs it to the DC power system 102. The power converter 1 includes multiple sets of arms 103 and arms 104. Arms 103 and 104 are connected in series with each other. Multiple sets of arms 103 and 104 are connected in parallel with each other. A transformer 101 is connected between arms 103 and 104. Arms 103 and 104 each include multiple submodules 10 connected in series with each other.

[0011] Referring to Figure 2, each of the submodules 10 includes, for example, switching elements 105a, 105b, diodes 106a, 106b, capacitor 107, and connecting wires 108a, 108b.

[0012] The switching elements 105a and 105b are, for example, IGBTs (Insulated Gate Bipolar Transistors). The switching element 105a and the switching element 105b are connected in series with each other.

[0013] The diode 106a is connected in anti-parallel to the switching element 105a. The diode 106b is connected in anti-parallel to the switching element 105b. The capacitor 107 is connected in parallel to the switching elements 105a and 105b.

[0014] The connection wire 108a is connected to the emitter terminal of the switching element 105a and the collector terminal of the switching element 105b. The connection wire 108b is connected to the emitter terminal of the switching element 105b. The connection wire 108a of the sub-module 10 is connected to the connection wire 108b of another sub-module 10 adjacent to the sub-module 10. Thus, the sub-module 10 constitutes a half-bridge type converter cell.

[0015] Referring to FIG. 1, the power conversion device 1 includes a cooling pipe 4 and a refrigerant circulator 7. The cooling pipe 4 is formed of an insulating material such as, for example, a fluorine-based insulating resin. The cooling pipe 4 is connected to the refrigerant circulator 7 and a plurality of sub-modules 10. The cooling pipe 4 includes a supply pipe 5 and a discharge pipe 6. The refrigerant flows through the cooling pipe 4. The refrigerant circulator 7 includes a pump (not shown). The refrigerant circulator 7 supplies the refrigerant to the plurality of sub-modules 10 through the supply pipe 5. The refrigerant is, for example, water or the like. The plurality of sub-modules 10 are cooled by the refrigerant. The refrigerant heated by the plurality of sub-modules 10 returns to the refrigerant circulator 7 through the discharge pipe 6. The refrigerant circulator 7 cools the refrigerant heated by the plurality of sub-modules 10 and supplies the refrigerant to the plurality of sub-modules 10 again through the supply pipe 5.

[0016] Referring to FIG. 1, the power conversion device 1 includes an optical fiber cable 8 and a controller 9. The optical fiber cable 8 is connected to the controller 9 and a plurality of sub-modules 10. The controller 9 transmits control signals to the plurality of sub-modules 10 through the optical fiber cable 8. Thus, the controller 9 controls the plurality of sub-modules 10.

[0017] Referring to FIGS. 3 to 9, the configuration of the power conversion device 1 according to the embodiment will be described. The power conversion device 1 includes converter valve towers 2 and 3.

[0018] The converter valve tower 2 includes a plurality of units 13a, 13b, 13c, 13d, a support insulator 12, and racks 20 and 20b. The converter valve tower 2 may further include a base 11. The converter valve tower 2 may further include a top shield 18 and a side shield 19. The converter valve tower 2 may further include a first fixing member 27 and a second fixing member 30.

[0019] The converter valve tower 2 is fixed to the installation surface 50. For example, the base 11 is fixed to the installation surface 50. The base 11 is formed of, for example, steel. The support insulator 12 is fixed to the base 11. The support insulator 12 extends in the third direction DR3. The third direction DR3 is the vertical direction. The support insulator 12 supports the plurality of units 13a, 13b, 13c, 13d. The support insulator 12 is formed of an insulating material such as, for example, fiber reinforced plastic (FRP) or ceramic.

[0020] The plurality of units 13a, 13b, 13c, 13d are stacked in the third direction DR3. Each of the plurality of units 13a, 13b, 13c, 13d includes a plurality of sub-modules 10, a mounting plate 17, and a frame 14. The frame 14 includes columns 15 and connection insulators 16.

[0021] Multiple submodules 10 are mounted on a mounting plate 17. The mounting surface of the mounting plate 17 on which the multiple submodules 10 are mounted extends in a first direction DR1 and a second direction DR2. The first direction DR1 is perpendicular to the third direction DR3. The second direction DR2 is perpendicular to both the first direction DR1 and the third direction DR3. The first direction DR1 and the second direction DR2 define a horizontal plane. The mounting plate 17 is fixed to the frame 14. The mounting plate 17 is fixed to the support columns 15, for example, using bolts. The mounting plate 17 is formed of an insulating material, for example, glass epoxy resin.

[0022] The support column 15 is made of a material such as steel. The support column 15 of the lowest unit 13a among the multiple units 13a, 13b, 13c, and 13d is fixed to the support insulator 12 using bolts or the like.

[0023] The connecting insulator 16 connects the support columns 15 included in adjacent units among the multiple units 13a, 13b, 13c, and 13d. The connecting insulator 16 included in the uppermost unit 13d connects the support column 15 included in the uppermost unit 13d to the top shield 18. The connecting insulator 16 is fixed to the support column 15 and the top shield 18, for example, using bolts. The connecting insulator 16 is made of an insulating material such as fiber-reinforced plastic (FRP) or ceramic. The connecting insulator 16 may be made of the same material as the support insulator 12.

[0024] The top shield 18 is located at the very top of the transducer valve tower 2. The top shield 18 is fixed, for example, to a connecting insulator 16 included in the uppermost unit 13d of the multiple units 13a, 13b, 13c, 13d, using bolts. The side shields 19 are located on the sides of the transducer valve tower 2. The side shields 19 are fixed, for example, to a support column 15, using bolts. The top shield 18 and side shields 19 are made of a metal such as aluminum. The top shield 18 and side shields 19 mitigate the electric field incident on the multiple submodules 10 from around the transducer valve tower 2, thereby protecting the multiple submodules 10 from said electric field. The top shield 18 and side shields 19 also mitigate the electric field emitted from the multiple submodules 10 to around the transducer valve tower 2.

[0025] Referring to Figures 3, 4, and 6 through 8, the rack 20 supports the cooling pipes 4 (more specifically, the supply pipes 5) for example, in the direction of gravity. The rack 20 includes a plurality of support rods 21, 22 and a plurality of plates (top plate 23, intermediate plates 24, 25, and bottom plate 26).

[0026] Referring to Figures 4 and 6 through 8, the multiple plates (top plate 23, intermediate plates 24, 25, and bottom plate 26) are formed of an insulating material such as glass epoxy resin. The multiple plates include the top plate 23, the intermediate plates 24, 25, and the bottom plate 26.

[0027] The top plate 23 is positioned closest to the multiple units 13a, 13b, 13c, and 13d among the multiple plates (top plate 23, intermediate plates 24, 25, and bottom plate 26). The top plate 23 is fixed to the support column 15 of the lowest unit 13a. The bottom plate 26 is positioned closest to the base 11 or the mounting surface 50 among the multiple plates. The top plate 23 and the bottom plate 26 are, for example, metal plates.

[0028] Intermediate plates 24 and 25 are positioned between the upper plate 23 and the lower plate 26. Intermediate plates 24 and 25 are positioned below the lowest unit 13a among the multiple units 13a, 13b, 13c, and 13d. Intermediate plates 24 and 25 are, for example, insulating plates. Intermediate plates 24 and 25 are arranged alternately.

[0029] Each of the multiple plates (upper plate 23, intermediate plates 24, 25, lower plate 26) has an upper main surface facing the multiple units 13a, 13b, 13c, 13d and a lower main surface facing the base 11 or the installation surface 50. For example, each intermediate plate 24 has an upper main surface 24a and a lower main surface 24b. The upper and lower main surfaces of each of the multiple plates are, for example, oriented in the vertical direction. The cooling pipe 4 (supply pipe 5) is fixed to the upper main surface 24a of the intermediate plate 24 using a first fixing member 27. The cooling pipe 4 is fixed to at least two of the intermediate plates 24 of the multiple plates (upper plate 23, intermediate plates 24, 25, lower plate 26). The cooling pipe 4 is not fixed to the intermediate plate 25. The cooling pipe 4 is fixed to the lower plate 26.

[0030] In rack 20, the cooling pipe 4 extends in a third direction DR3 while meandering in a first direction DR1. The third direction DR3 is vertical. In rack 20, the length of the cooling pipe 4 in the first direction DR1 is greater than the length of each of the multiple plates (top plate 23, intermediate plates 24, 25, bottom plate 26) in the first direction DR1. In the first direction DR1, the cooling pipe 4 may protrude from each of the ends of the intermediate plates 24, 25. In the first direction DR1, the cooling pipe 4 may protrude from each of the ends of the top plate 23 and the bottom plate 26.

[0031] Referring to Figures 4 and 6 through 8, multiple plates (top plate 23, intermediate plates 24, 25, bottom plate 26) are stacked in a third direction DR3 via multiple support rods 21, 22. The multiple support rods 21, 22 include odd-numbered support rods 21 and even-numbered support rods 22. Specifically, the top plate 23 and intermediate plate 24 are stacked via support rods 21. Intermediate plate 24 and intermediate plate 25 are stacked via support rods 21, 22. Intermediate plate 25 and bottom plate 26 are stacked via support rods 21. The bottom plate 26 is supported by the base 11 via support rods 22.

[0032] Referring to Figures 7 and 8, in a plan view from the direction in which the multiple plates (top plate 23, intermediate plates 24, 25, bottom plate 26) are stacked (third direction DR3), the multiple support rods 21, 22 are fixed to the edges (e.g., edges 24e, 24f) of each of the multiple plates in the second direction DR2. Each edge of the multiple plates refers to the first and second parts of the three parts when each of the multiple plates is equally divided into three parts in the second direction DR2. The first part is the part of the three parts that includes one end of each of the multiple plates in the second direction DR2. The second part is the part of the three parts that includes the other end of each of the multiple plates in the second direction DR2.

[0033] Referring to Figures 4, 6, and 7, in a plan view from the direction in which the multiple plates (top plate 23, intermediate plates 24, 25, bottom plate 26) are stacked (third direction DR3), the support rods 21 for odd-numbered stages and the support rods 22 for even-numbered stages are arranged alternately in the first direction DR1. The first direction DR1 is the direction along the longitudinal direction of the cooling pipes 4 in a plan view of the rack 20 from the third direction DR3.

[0034] The odd-numbered support rods 21 include a first support rod 21a and a second support rod 21b. In a plan view from the third direction DR3, the second support rod 21b is positioned offset from the first support rod 21a in the first direction DR1. The odd-numbered support rods 21 may include, for example, two first support rods 21a and two second support rods 21b. The even-numbered support rods 22 include a third support rod 22a and a fourth support rod 22b. In a plan view from the third direction DR3, the fourth support rod 22b is positioned offset from the third support rod 22a in the first direction DR1. The even-numbered support rods 22 may include, for example, two third support rods 22a and two fourth support rods 22b. In a plan view from the third direction DR3, the third support rod 22a is positioned offset from the first support rod 21a in the first direction DR1. In a plan view from the third direction DR3, the fourth support rod 22b is positioned offset from the second support rod 21b in the first direction DR1.

[0035] In a plan view from the third direction DR3, the first gap G1 between the first support rod 21a and the third support rod 22a, and the second gap G2 between the second support rod 21b and the fourth support rod 22b are each smaller than the third gap G3 between the second support rod 21b and the third support rod 22a. Therefore, as shown in Figure 9, the rack 20 has a first creepage path 35 and a second creepage path 36. The first creepage path 35 and the second creepage path 36 are paths for leakage currents flowing from the multiple submodules 10 to the installation surface 50. The first gap G1 may be equal to the second gap G2. That is, the first creepage distance of the rack 20, which is the length of the first creepage path 35, may be equal to the second creepage distance of the rack 20, which is the length of the second creepage path 36. The creepage distance of the cooling pipe 4 is greater than the first and second creepage distances of the rack 20.

[0036] Referring to Figures 6 to 9, the first fixing member 27 fixes the cooling pipe 4 to the intermediate plate 24. The first fixing member 27 includes, for example, a support member 28 and a fastener 29. The support member 28 is, for example, a support plate or a support block. The support member 28 is fixed to the upper main surface 24a of the intermediate plate 24. A recess 28a is formed in the support member 28. The cooling pipe 4 (supply pipe 5) is fitted into the recess 28a. The cooling pipe 4 is fixed to the support member 28 using a fastener 29. The fastener 29 is, for example, a cable tie.

[0037] Referring to Figures 4 and 6 to 9, the optical fiber cable 8 may be fixed to the rack 20. Specifically, the second fixing member 30 fixes the optical fiber cable 8 to the upper main surface 24a of at least the intermediate plate 24 among the multiple plates (upper plate 23, intermediate plates 24, 25, lower plate 26). The optical fiber cable 8 extends in the third direction DR3 while meandering in the first direction DR1. The creepage distance of the optical fiber cable 8 is greater than the first creepage distance and the second creepage distance of the rack 20. The second fixing member 30 is, for example, a fastener such as a cable tie.

[0038] Referring to Figures 3 and 5, rack 20b is configured similarly to rack 20. Rack 20b supports the cooling pipe 4 (more specifically, the exhaust pipe 6).

[0039] Referring to Figures 4 and 5, the converter valve tower 3 is positioned in the first direction DR1 relative to the converter valve tower 2. The first direction DR1 is the depth direction of the power converter 1. The converter valve tower 3 is configured similarly to the converter valve tower 2.

[0040] Referring to Figure 10, in the first modified example of this embodiment, the odd-numbered support rods 21 include one first support rod 21a and one second support rod 21b. In a plan view from the third direction DR3, the second support rod 21b is offset from the first support rod 21a in the first direction DR1 and the second direction DR2. The even-numbered support rods 22 include one third support rod 22a and one fourth support rod 22b. In a plan view from the third direction DR3, the fourth support rod 22b is offset from the third support rod 22a in the first direction DR1 and the second direction DR2.

[0041] In a plan view from the third direction DR3, the first support rod 21a and the second support rod 21b are arranged along the first diagonal 24i of the upper main surface 24a of the intermediate plate 24. In a plan view from the third direction DR3, the third support rod 22a and the fourth support rod 22b are arranged along the first diagonal 24i of the upper main surface 24a of the intermediate plate 24. In a plan view from the third direction DR3, the first line connecting the first support rod 21a and the second support rod 21b does not intersect with the second line connecting the third support rod 22a and the fourth support rod 22b. In a plan view from the third direction DR3, the fourth support rod 22b is arranged parallel to the second support rod 21b is arranged parallel to the first support rod 21a.

[0042] Referring to Figure 11, in the second modified example of this embodiment, similar to the first modified example, the odd-numbered support rods 21 include one first support rod 21a and one second support rod 21b, and the even-numbered support rods 22 include one third support rod 22a and one fourth support rod 22b. In a plan view from the third direction DR3, the second support rod 21b is offset from the first support rod 21a in the first direction DR1 and the second direction DR2. In a plan view from the third direction DR3, the fourth support rod 22b is offset from the third support rod 22a in the first direction DR1 and the second direction DR2.

[0043] In a plan view from the third direction DR3, the second support rod 21b is positioned along the first diagonal 24i of the upper main surface 24a of the intermediate plate 24. In a plan view from the third direction DR3, the fourth support rod 22b is positioned along the second diagonal 24j of the upper main surface 24a of the intermediate plate 24, which intersects the first diagonal. In a plan view from the third direction DR3, the first line connecting the first support rod 21a and the second support rod 21b intersects the second line connecting the third support rod 22a and the fourth support rod 22b.

[0044] The effects of the power converter 1 of this embodiment will be explained. The power converter 1 of this embodiment comprises a plurality of units 13a, 13b, 13c, 13d, a support insulator 12, a cooling pipe 4, and a rack 20. The plurality of units 13a, 13b, 13c, 13d are stacked. Each of the plurality of units 13a, 13b, 13c, 13d includes a plurality of submodules 10. The support insulator 12 supports the plurality of units 13a, 13b, 13c, 13d. The cooling pipe 4 is connected to the plurality of submodules 10. A refrigerant for cooling the plurality of submodules 10 is supplied to the plurality of submodules 10 through the cooling pipe 4. The rack 20 supports the cooling pipe 4. The rack 20 includes a plurality of support rods 21, 22 and a plurality of plates (upper plate 23, intermediate plates 24, 25, and lower plate 26) stacked via the plurality of support rods 21, 22. The cooling pipe 4 is fixed to at least two of the multiple plates (for example, the intermediate plate 24) and is meandering. At least two of the plates are positioned below the lowest unit 13a of the multiple units 13a, 13b, 13c, and 13d.

[0045] Since the cooling pipe 4 is fixed to at least two of the multiple plates (upper plate 23, intermediate plates 24, 25, and lower plate 26) (for example, the intermediate plate 24), the seismic resistance of the cooling pipe 4 is improved. The power converter 1 has improved seismic resistance. In addition, because the cooling pipe 4 is meandering, the creepage distance of the cooling pipe 4 is increased. The leakage current flowing from the multiple submodules 10 to the installation surface 50 through the creepage path of the cooling pipe 4 is reduced. The height of the cooling pipe 4 can be reduced, and therefore the height of the power converter 1 can be reduced.

[0046] In the power converter 1 of this embodiment, the multiple support rods 21 and 22 include odd-numbered support rods 21 and even-numbered support rods 22. In a plan view from the direction in which the multiple plates (upper plate 23, intermediate plates 24, 25, and lower plate 26) are stacked (third direction DR3), the odd-numbered support rods 21 and even-numbered support rods 22 are arranged alternately in the first direction DR1. The first direction DR1 is the direction along the longitudinal direction of the cooling pipe 4 in a plan view from the direction in which the multiple plates are stacked.

[0047] As a result, the second moment of area of ​​the rack 20 increases, improving the bending rigidity of the rack 20. The seismic resistance of the cooling pipe 4 improves, improving the seismic resistance of the power converter 1. In addition, in a plan view from the direction in which the multiple plates (top plate 23, intermediate plates 24, 25, and bottom plate 26) are stacked (third direction DR3), the creepage distance of the rack 20 increases compared to when the support rods 21 of the odd-numbered stages are positioned at the same location as the support rods 22 of the even-numbered stages. The height of the rack 20 can be reduced, and the height of the power converter 1 can be reduced.

[0048] In the power converter 1 of this embodiment, the odd-numbered support rods 21 include a first support rod 21a and a second support rod 21b. The even-numbered support rods 22 include a third support rod 22a and a fourth support rod 22b. In a plan view from the direction in which the multiple plates (top plate 23, intermediate plates 24, 25 and bottom plate 26) are stacked (third direction DR3), the third support rod 22a is positioned offset from the first support rod 21a in the first direction DR1. In a plan view from the direction in which the multiple plates are stacked, the fourth support rod 22b is positioned offset from the second support rod 21b in the first direction DR1. In a plan view from the direction in which the multiple plates are stacked, the first spacing G1 between the first support rod 21a and the third support rod 22a, and the second spacing G2 between the second support rod 21b and the fourth support rod 22b are each smaller than the third spacing G3 between the second support rod 21b and the third support rod 22a.

[0049] As a result, the second moment of area of ​​the rack 20 increases, improving the bending rigidity of the rack 20. The seismic resistance of the cooling pipe 4 improves, improving the seismic resistance of the power converter 1. In addition, the creepage distance of the rack 20 increases compared to when the odd-numbered support rods 21 are positioned at the same location as the even-numbered support rods 22 in a plan view from the direction in which the multiple plates (top plate 23, intermediate plates 24, 25, and bottom plate 26) are stacked (third direction DR3). The height of the rack 20 can be reduced, and the height of the power converter 1 can be reduced. Furthermore, the difference between the multiple creepage distances of the rack 20 (for example, the length of the first creepage path 35 and the length of the second creepage path 36) decreases. The distribution of the electric field formed by the leakage current flowing from the multiple submodules 10 to the installation surface 50 through the multiple creepage paths of the rack 20 becomes more uniform. As a result, the electrical insulation performance of the power converter 1 improves, and the power converter 1 can be miniaturized while preventing electrical dielectric breakdown from occurring in the power converter 1.

[0050] In the power converter 1 of this embodiment, the first interval G1 is equal to the second interval G2. Therefore, the difference between the multiple creepage distances of the rack 20 (for example, the length of the first creepage path 35 and the length of the second creepage path 36) is further reduced. The distribution of the electric field formed by the leakage current flowing from the multiple submodules 10 to the installation surface 50 through the multiple creepage paths of the rack 20 becomes more uniform. As a result, the electrical insulation performance of the power converter 1 is improved, and the power converter 1 can be miniaturized while preventing electrical dielectric breakdown from occurring in the power converter 1.

[0051] In the power converter 1 of this embodiment, in a plan view from the direction in which the multiple plates (top plate 23, intermediate plates 24, 25, and bottom plate 26) are stacked (third direction DR3), the multiple support rods 21, 22 are fixed to the edges (e.g., edges 24e, 24f) of each of the multiple plates in the second direction DR2. The second direction DR2 is a direction perpendicular to the first direction DR1 in a plan view from the direction in which the multiple plates are stacked.

[0052] Therefore, the bending rigidity of rack 20 is improved. The seismic resistance of cooling pipe 4 is improved, and the seismic resistance of power converter 1 is improved.

[0053] In the power converter 1 of this embodiment, the multiple plates (upper plate 23, intermediate plates 24, 25, and lower plate 26) include a first plate (intermediate plate 24) to which the cooling pipes 4 are fixed, and a second plate (intermediate plate 25) to which the cooling pipes 4 are not fixed. The first plate and the second plate are stacked alternately.

[0054] Therefore, the creepage distance of the rack 20 (for example, the length of the first creepage path 35 and the length of the second creepage path 36) increases. The leakage current through the creepage paths of the rack 20 (for example, the first creepage path 35 and the second creepage path 36) decreases. The height of the rack 20 can be reduced, and the height of the power converter 1 can be reduced.

[0055] In the power converter 1 of this embodiment, the creepage distance of the cooling pipe 4 is greater than the creepage distance of the rack 20.

[0056] Therefore, the leakage current passing through the creepage path of the cooling pipe 4 is reduced. The height of the cooling pipe 4 can be reduced, and thus the height of the power converter 1 can be reduced.

[0057] The power conversion device 1 of this embodiment further includes a first fixing member 27 that fixes the cooling pipe 4 to at least two of the multiple plates (upper plate 23, intermediate plates 24, 25 and lower plate 26), specifically the intermediate plate 24.

[0058] Since the cooling pipe 4 is fixed to at least two of the multiple plates (upper plate 23, intermediate plates 24, 25, and lower plate 26) (for example, the intermediate plate 24), the seismic resistance of the cooling pipe 4 is improved. The power converter 1 has improved seismic resistance.

[0059] The power converter 1 of this embodiment further comprises optical fiber cables 8 connected to a plurality of submodules 10. The optical fiber cables 8 are fixed to a rack 20.

[0060] The rack 20 can be used to secure both the cooling pipe 4 and the fiber optic cable 8. This can reduce the cost of the power converter 1.

[0061] In the power conversion device 1 of this embodiment, the optical fiber cable 8 is fixed to at least two of the multiple plates (upper plate 23, intermediate plates 24, 25 and lower plate 26), specifically the intermediate plate 24, and is meandering.

[0062] Because the optical fiber cable 8 is meandering, the creepage distance of the optical fiber cable 8 increases. The leakage current flowing from the multiple submodules 10 to the installation surface 50 through the creepage path of the optical fiber cable 8 decreases. The height of the optical fiber cable 8 can be reduced, and the height of the power converter 1 can be reduced.

[0063] The embodiments and variations thereof disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than the foregoing description and is intended to include all modifications within the meaning and scope of the claims equivalents. [Explanation of Symbols]

[0064] 1 Power converter, 2,3 Converter valve tower, 4 Cooling pipe, 5 Supply pipe, 6 Discharge pipe, 7 Refrigerant circulator, 8 Fiber optic cable, 9 Controller, 10 Submodule, 11 Base, 12 Support insulator, 13a,13b,13c,13d Unit, 14 Frame, 15 Support column, 16 Connecting insulator, 17 Mounting plate, 18 Top shield, 19 Side shield, 20,20b Rack, 21,22 Support rod, 21a First support rod, 21b Second support rod, 22a Third support rod, 22b Fourth support rod, 23 Top plate, 24,25 Intermediate plate, 24a Upper main surface, 24b Lower main surface, 24e,24f Edge, 24i First diagonal, 24j Second diagonal, 26 Bottom plate, 27 1st fixing member, 28 support member, 28a recess, 29 fastener, 30 second fixing member, 35 first creepage path, 36 second creepage path, 50 installation surface, 100 AC power system, 101 transformer, 102 DC power system, 103, 104 arms, 105a, 105b switching elements, 106a, 106b diodes, 107 capacitors, 108a, 108b connecting wires.

Claims

1. comprising a plurality of stacked units, each of which includes a plurality of submodules, Support insulators that support the plurality of units, Cooling pipes connected to the aforementioned multiple submodules, It comprises a rack that supports the cooling pipe, The refrigerant used to cool the plurality of submodules is supplied to the plurality of submodules through the cooling pipes. The rack includes a plurality of support rods and a plurality of plates stacked on top of each other via the plurality of support rods. The cooling pipe is fixed to at least two of the plurality of plates and is meandering. The at least two plates are positioned below the lowest unit among the plurality of units, The aforementioned plurality of support rods include odd-numbered support rods and even-numbered support rods. In a plan view from the direction in which the aforementioned multiple plates are stacked, the support rods for the odd-numbered rows and the support rods for the even-numbered rows are arranged alternately in the first direction. The first direction is the direction along the longitudinal direction of the cooling pipe in the plan view, in the power conversion device.

2. The odd-numbered support rods include a first support rod and a second support rod. The aforementioned even-numbered support rods include a third support rod and a fourth support rod. In the plan view, the third support rod is positioned offset in the first direction relative to the first support rod. In the plan view, the fourth support rod is positioned offset in the first direction relative to the second support rod. The power conversion device according to claim 1, wherein, in the plan view, the first distance between the first support rod and the third support rod and the second distance between the second support rod and the fourth support rod are each smaller than the third distance between the second support rod and the third support rod.

3. The power conversion device according to claim 2, wherein the first interval is equal to the second interval.

4. In the plan view, the plurality of support rods are fixed to the edge of each of the plurality of plates in the second direction. The power conversion device according to claim 1, wherein the second direction is a direction perpendicular to the first direction in the plan view.

5. comprising a plurality of stacked units, each of which includes a plurality of submodules, Support insulators that support the plurality of units, Cooling pipes connected to the aforementioned multiple submodules, It comprises a rack that supports the cooling pipe, The refrigerant used to cool the plurality of submodules is supplied to the plurality of submodules through the cooling pipes. The rack includes a plurality of support rods and a plurality of plates stacked on top of each other via the plurality of support rods. The cooling pipe is fixed to at least two of the plurality of plates and is meandering. The at least two plates are positioned below the lowest unit among the plurality of units, The plurality of plates include a first plate to which the cooling pipe is fixed and a second plate to which the cooling pipe is not fixed. A power conversion device in which the first plate and the second plate are stacked alternately.

6. The power conversion device according to any one of claims 1 to 5, wherein the creepage distance of the cooling pipe is greater than the creepage distance of the rack.

7. The power conversion device according to any one of claims 1 to 5, further comprising a fixing member for fixing the cooling pipe to the at least two plates.

8. The further comprising optical fiber cables connected to the aforementioned plurality of submodules, The power conversion device according to any one of claims 1 to 5, wherein the optical fiber cable is fixed to the rack.

9. The power conversion device according to claim 8, wherein the optical fiber cable is fixed to at least two of the plurality of plates and is meandering.

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